From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Burnt-out cut-out on Chassis No. 68-HC, suggesting probable external electrical faults as the cause.
| Identifier | ExFiles\Box 70\3\ scan0197 | |
| Date | 16th April 1926 | |
| X8783. Model. C. to BP. [struck through] C. to Derby. [struck through] C. to EFC. Hm{Capt. W. Hallam - Head Repairs}/NRC{N. R. Chandler}4/EW16.4.26. Re Chassis No. 68-HC. D/BP/F18/H15.4.26. With reference to the Cut-out returned, this has been burnt out by the application of a voltage considerably in excess of the normal. No examination of the Cut-out alone will reveal the cause of the trouble, as this is entirely external to the cut-out. The most likely cause we can suggest is that the battery circuit is either broken or making defective contact somewhere. The points to look for would be - Loose or broken connections on top of accumulator. Loose or broken connector inside accumulator. Accumulator acid level allowed to run very low (as result of excessive overcharging), and thereby increasing the resistance and producing a corresponding rise in voltage. Any breakage or undue resistance in any part of the battery charging circuit. We trust you looked into these matters and found out the cause of the trouble. If you merely replaced the cut-out by another, there is every possibility that the same thing will happen again. In future cases of trouble affecting a cut-out on either Phantom or 20HP. car, please always return the distributor board complete; we do not on any account supply cut-outs separately. Kindly let us know how you replaced the burnt cut-out you have returned. We should think it very probable that the dynamo suffered considerably as a result of the excessive voltage necessary to burn out the cut-out. Did you examine the brushes and commutator and ascertain if the commutator cont'd.{John DeLooze - Company Secretary} | ||